This paper proposes a new modied architecture for AC microgrid consisting of multiple
grid-supporting master units (MUs) and multiple grid-feeding slave units (SUs). In this study, a coordinated
four-layer hierarchal control (HC) approach is applied to the proposed structure for allowing the MUs, SUs
and loads to be easily integrated as a microgrid and operated in both grid-integrated and standalone operation
mode. The proposed structure of the AC microgrid enhances the system redundancy to prevent the single
point of failure of MU and has more stability, efciency, exibility and reliability than the conventional
structures. Furthermore, optimal design guidelines, based on a new hybrid Harries hawks and particle swarm
optimization algorithm (H-HHOPSO) with the cooperation of different types of proposed multi-objective
functions, are presented to fulll the study objectives. The optimization constraints/objectives are employed
for optimal parameters selection of HC controllers to improve the power quality, enhance dynamic and
steady-state performance and guarantee a seamless transition between operation modes. To accomplish this
work, the newly modied structure is modeled, constructed in MATLAB/SIMULINK and tested under the
variations of generations and loads. This structure is also examined when the fault occurs at any one of the
MUs and during the connecting and disconnecting of utility grid. This testing is to verify its exibility and
reliability, and conrm the effectiveness and robustness of the proposed optimal controllers. Additionally,
the experimental work is carried out using the hardware-in-the-loop real-time emulation to prove the optimal
controllers' feasibility. Finally, the experimental and simulation results are compared. |